Laboratory and Clinical Predictors of Disease Progression following Initiation of Combination Therapy in HIV-Infected Adults in Thailand

Background: Data on determinants of long-term disease progression in HIV-infected patients on antiretroviral therapy (ART) are limited in low and middle-income settings. Methods: Effects of current CD4 count, viral load and haemoglobin and diagnosis of AIDS-defining events (ADEs) after start of combination ART (cART) on death and new ADEs were assessed using Poisson regression, in patient aged ≥18 years within a multi-centre cohort in Thailand. Results: Among 1,572 patients, median follow-up from cART initiation was 4.4 (IQR 3.6–6.3) years. The analysis of death was based on 60 events during 6,573 person-years; 30/50 (60%) deaths with underlying cause ascertained were attributable to infections. Analysis of new ADE included 192 events during 5,865 person-years; TB and Pneumocystis jiroveci pneumonia were the most commonly presented first new ADE (35% and 20% of cases, respectively). In multivariable analyses, low current CD4 count after starting cART was the strongest predictor of death and of new ADE. Even at CD4 above 200 cells/mm3, survival improved steadily with CD4, with mortality rare at ≥500 cells/mm3 (rate 1.1 per 1,000 person-years). Haemoglobin had a strong independent effect, while viral load was weakly predictive with poorer prognosis only observed at ≥100,000 copies/ml. Mortality risk increased following diagnosis of ADEs during cART. The decline in mortality rate with duration on cART (from 21.3 per 1,000 person-years within first 6 months to 4.7 per 1,000 person-years at ≥36 months) was accounted for by current CD4 count. Conclusions: Patients with low CD4 count or haemoglobin require more intensive diagnostic and treatment of underlying causes. Maintaining CD4≥500 cells/mm3 minimizes mortality. However, patient monitoring could potentially be relaxed at high CD4 count if resources are limited. Optimal ART monitoring strategies in low-income settings remain a research priority. Better understanding of the aetiology of anaemia in patients on ART could guide prevention and treatment

Phytoplankton diversity and its relationships to the physico-chemical environment in the Banglang Reservoir, Yala Province

The diversity of phytoplankton and its relationships to the physico- chemical environment were studied in Banglang Reservoir, located on the Pattani River in Southern Thailand. Samples were collected monthly from May 2000 to April 2001 at three stations and three different depths: water surface, 10, and 30 meters. Physico-chemical parameters: temperature, pH, dissolved oxygen, alkalinity, conductivity, water transparency, and nutrients were measured simultaneously. One-hundred and thirty-five species in seven divisions of phytoplankton were found. The greatest number of species were in Division Chlorophyta (50%), followed by Cyanophyta (21%), Bacillariophyta (13%), Pyrrophyta (6%), Cryptophyta (4%), Chrysophyta (3%) and Euglenophyta (3%). The most diverse genus was Staurastrum (15 species). Phytoplankton density ranged from zero to 2.1x109 cells.m-3. Microcystis aeruginosa Kutzing in January at 30 m at the lacustrine zone had the highest phytoplankton density. By applying a PCA(principal components analysis) using the MVSP statistical analysis program on the abundance of species, it was found that Cyclotella meneghiniana Kutzing and Melosira varians Agardh were the most abundant in each station. Diversity index (Simpson’s diversity index) was maximum at 10 m at the transition zone and lowest at the outflow zone. The factors affecting the phytoplankton species by Canonical correspondence analysis ordination (PC-ORD program)were alkalinity, water temperature, water transparency, nutrients and conductivity. When the water quality parameters were classified by the trophic level, Banglang Reservoir belonged to oligo-mesotrophic status. Furthermore, Cyclotella meneghiniana Kutzing and Melosira varians Agardh could be used as the phytoplankton indicator of oligo-mesotrophic reservoir

Laboratory and clinical predictors of disease progression following initiation of combination therapy in HIV-infected adults in Thailand

Background: Data on determinants of long-term disease progression in HIV-infected patients on antiretroviral therapy (ART) are limited in low and middle-income settings. Methods: Effects of current CD4 count, viral load and haemoglobin and diagnosis of AIDS-defining events (ADEs) after start of combination ART (cART) on death and new ADEs were assessed using Poisson regression, in patient aged >= 18 years within a multi-centre cohort in Thailand. Results: Among 1,572 patients, median follow-up from cART initiation was 4.4 (IQR 3.6-6.3) years. The analysis of death was based on 60 events during 6,573 person-years; 30/50 (60%) deaths with underlying cause ascertained were attributable to infections. Analysis of new ADE included 192 events during 5,865 person-years; TB and Pneumocystis jiroveci pneumonia were the most commonly presented first new ADE (35% and 20% of cases, respectively). In multivariable analyses, low current CD4 count after starting cART was the strongest predictor of death and of new ADE. Even at CD4 above 200 cells/mm 3, survival improved steadily with CD4, with mortality rare at >= 500 cells/mm 3 (rate 1.1 per 1,000 person-years). Haemoglobin had a strong independent effect, while viral load was weakly predictive with poorer prognosis only observed at >= 100,000 copies/ml. Mortality risk increased following diagnosis of ADEs during cART. The decline in mortality rate with duration on cART (from 21.3 per 1,000 person-years within first 6 months to 4.7 per 1,000 person-years at >= 36 months) was accounted for by current CD4 count. Conclusions: Patients with low CD4 count or haemoglobin require more intensive diagnostic and treatment of underlying causes. Maintaining CD4 >= 500 cells/mm(3) minimizes mortality. However, patient monitoring could potentially be relaxed at high CD4 count if resources are limited. Optimal ART monitoring strategies in low-income settings remain a research priority. Better understanding of the aetiology of anaemia in patients on ART could guide prevention and treatment

Revisiting the role of neutralizing antibodies in mother-to-child transmission of HIV-1

We analyzed the association between mother-to-child transmission (MTCT) of human immunodeficiency virus type 1 (HIV-1) and maternal neutralizing antibodies to heterologous primary isolates of various HIV-1 clades, to test the hypothesis that protective antibodies are those with broad neutralizing activity. Our study sample included 90 Thai women for whom the timing of HIV-1 transmission ( in utero or intrapartum) was known. The statistical analysis included a conditional logistic-regression model to control for both plasma viral load and duration of zidovudine prophylaxis. The higher the titer of neutralizing antibodies to a heterologous strain of the same clade, the lower the rate of MTCT of HIV-1. More specifically, high levels of neutralizing antibodies to the MBA (CRF01_AE) strain were associated with low intrapartum transmission of HIV-1. This suggested that such heterologous neutralizing antibodies may be involved in the natural prevention of late perinatal HIV transmission. These data are consistent with the hypothesis that the use of some antibodies might help to prevent perinatal HIV transmission, through passive immunoprophylaxis. Moreover, the study of humoral factors associated with MTCT of HIV-1 may identify correlates of protection that should help in the design of efficient HIV/acquired immunodeficiency syndrome vaccines

Laboratory and Clinical Predictors of Disease Progression following Initiation of Combination Therapy in HIV-Infected Adults in Thailand

Background Data on determinants of long-term disease progression in HIV-infected patients on antiretroviral therapy (ART) are limited in low and middle-income settings. Methods Effects of current CD4 count, viral load and haemoglobin and diagnosis of AIDS-defining events (ADEs) after start of combination ART (cART) on death and new ADEs were assessed using Poisson regression, in patient aged ≥18 years within a multi-centre cohort in Thailand. Results Among 1,572 patients, median follow-up from cART initiation was 4.4 (IQR 3.6–6.3) years. The analysis of death was based on 60 events during 6,573 person-years; 30/50 (60%) deaths with underlying cause ascertained were attributable to infections. Analysis of new ADE included 192 events during 5,865 person-years; TB and Pneumocystis jiroveci pneumonia were the most commonly presented first new ADE (35% and 20% of cases, respectively). In multivariable analyses, low current CD4 count after starting cART was the strongest predictor of death and of new ADE. Even at CD4 above 200 cells/mm3, survival improved steadily with CD4, with mortality rare at ≥500 cells/mm3 (rate 1.1 per 1,000 person-years). Haemoglobin had a strong independent effect, while viral load was weakly predictive with poorer prognosis only observed at ≥100,000 copies/ml. Mortality risk increased following diagnosis of ADEs during cART. The decline in mortality rate with duration on cART (from 21.3 per 1,000 person-years within first 6 months to 4.7 per 1,000 person-years at ≥36 months) was accounted for by current CD4 count. Conclusions Patients with low CD4 count or haemoglobin require more intensive diagnostic and treatment of underlying causes. Maintaining CD4≥500 cells/mm3 minimizes mortality. However, patient monitoring could potentially be relaxed at high CD4 count if resources are limited. Optimal ART monitoring strategies in low-income settings remain a research priority. Better understanding of the aetiology of anaemia in patients on ART could guide prevention and treatment